The Schuler is from this man named Schuler who was having sex with this girl doggy style. and she pointed at her ass. So he just put it in there. No lube or anything. She feel over crying and he just got dressed, said he was sorry and went home.
When you take a dump in a bathroom that does not belong to you and you neglect to flush, leaving the evidence for someone else to view upon entering the next day/week/etc. Also known as a dump-and-run, random shitting, mystery shitter syndrome (MSS).
After a night of drinking and partying:
Rod: Guys, I really need to shit. Do you mind if I use your shitter?
To show up at the last minute, after having not participated for an extended period; subsequently scamming free food, drinks, rides, etc. from other event attendees.
I haven't seen him in months, then he shows up, catches a ride out of town and makes us stop for Corn Nuts. He totally Schulered me!